Is It Safe to Run Furnace without Cover?- [Explained]

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After a whole day of stress, small details like the furnace cover shouldn’t be on your mind. But we do understand that it sure is something to worry about.

So you are wondering is it safe to run furnace without cover?

The safety of running furnaces without cover mainly depends on the time. If it is winter, then the answer is no. Because the exhaust gases can be sucked in, creating a fatal in-house environment. Though, in summer, keeping the furnace cover-free is the best because of mold and added bills.

I’ve explained all the reasoingn behind saying it’s not quite safe to run furnace without cover. All you need to do is to stick with us!

Why Shouldn’t You Run Furnace without Cover? 

Furnace covers in HVACs are always a tricky topic. While some may say it’s detrimental, others vouch for it. And it is sure to raise confusion. 

That’s why we have tried to organize it as much as possible.

how long can you run a furnace without a filter

And the answer is that it depends on which time you are running the furnace. Let us get on with it-

Negative Pressure

In the winter, running a furnace without cover causes toxic gas suction. Because it creates negative pressure. 

So, why does coverless furnace create negative pressure?

A coverless furnace creates negative pressure because of the added airflow. The reason is the little resistance in the blower compartment. Without the cover, there is a large opening and a lot of air comes rushing toward this path. 

Without the cover, there is close proximity to the fan. It means that the blower is drawing more and more air from the coverless opening. 

This excessive return of air through that particular furnace causes negative pressure. That is in the room the furnace is sitting. You can use RISEPRO Digital Air Pressure Meter too keep the air pressure in check in your house.

Now we understand if you did not know and now the air in your house feels heavy. You definitely shouldn’t breathe it and it is of utmost necessity that you get rid of it.

For this, the easiest solution would be to install the cover and run your HVAC. This would purify your return air and within some time it should be detoxicated. 

Toxic Gas Production:

Now, we know that fuel-burning compartments and gas water heaters produce toxic gases. 

These can be Carbon Monoxide and other dangerous elements. This is something you normally do not have to worry about. But without the cover, you have to.

Normally these hazardous gases are released outside. But with the negative pressure, these gases get pulled back in. This results in the reappearance of gases in your house which can be really harmful.

Aside from this, you can also use essential oil diffusers. So, what do you need to make essential oil diffusers? Mainly it’s a process that can be done with only three ingredients. Just by using alcohol, water, and different essential oils, it can be prepared. 

You can check out this video in order to perfectly execute the DIY essential oil diffuser.

Or you can also use Pure Daily Care essential oil diffuser to cleanse the air in your room. However, if you want an cheaper alternative then try out Homeweeks 300ml Essential Oil Diffuser.

It can help greatly to clean out the toxic air. Also, it is really helpful in reducing airborne bacteria. 

However, you might not like its fragrance depending on your choice. In that case, you can also remove that perfume-like odor from your room.

Electricity Bill Skyrocketing:

Also, there can be rust in the furnace. This rust will not let your furnace work efficiently thus increasing the electricity bill.

Electricity Bill Skyrocketing

So, why does your furnace cause high electricity bills?

There are different sensors in a furnace. In summer, they can needlessly consume excessive power. Also, if your furnace has a pilot light, it will definitely use up unnecessary gas in the summer. 

Also without the cover, your HVAC will draw in needless amounts of air throughout the passageway.

This unnecessary and extravagant usage will definitely contribute to raising your bills higher. 

Mold Generation:

This is the ONLY exception here where we are going to suggest to keep the cover off. However, if it’s winter then you must use the cover though.

A casualty that you have to consider with your HVAC is humidity. In the summer especially. At this time of the year, the air is specially moisturized as there is a high level of humidity.

If you keep the cover on the furnace during this time, then the humidity gets trapped within the pipelines. With the cover, the airflow is reduced in the furnace. This added level of humidity causes mold growth.

This will also cause bad smell coming out from the vent and walls.

Fixing the mold in your HVAC system is no DIY project. The only solution is to hire a professional HVAC installer. He will also be able to fix any additional problems in your furnace. 

Prerequisites and How to Install Cover in Furnace

Installing your furnace cover is not heavy-duty. But you just have to make sure of some things before installing them. 

First of all, check the air filter. Without the cover, it might have gotten dirty sooner than expected. If so, change the air filter. 

Then check if there are any error codes showing. There are different types of error codes for different problems in your HVAC. They are written on the back portion of the cover. 

Be sure to check and resolve them beforehand. 

After that, just get a screwdriver and install all the screws on the cover of your furnace. That is it. You are ready to go!

Also, it is important to ground your furnace so your HVAC works properly.

Frequently Asked Questions (FAQs) 

Why does the furnace shut off after putting on the cover?

The reason why your furnace shuts off after putting on the cover is low airflow. Without the proper amount of airflow, your HVAC units will heat up. This excessive heat might cause a malfunction in your HVAC. Also, dirty air filters tend to minimize or totally block the airflow in your furnace.

Can I run my furnace without a filter?

The answer is you should not. Running a furnace without a filter has many bad effects. While it is definitely bad for your health, it is also bad for your HVAC. With all the dirt piled up, it can overheat your heating system. It will ultimately wear down your HVAC and cause high electricity bills.

Why does my furnace catch fire?

Dirt around the motor can work as an insulator and cause the motor to overheat. Eventually causing your motor to catch fire. Then, faulty wiring might also cause high voltage and short circuits, leading to a fire. Also worn out and dry bearings can catch fire. So it is better to lubricate them as per need. 

How can I protect my furnace?

To protect your furnace, keep it turned off when the air is dusty. While renovation, ask your contractor to keep the project outside. Also, regularly check your air filters to see if they are clogged. Another thing you should do before the renovation is to install a fan on the window. It will blow the dust out from your home outside.


Now let’s hear your opinion. 

Were you able to understand if is it safe to run furnace without cover?

Here’s an extra tip for you. Be sure to replace your air filters after every 90 days or 3 months. This will keep your furnace performance boosted.

Be sure to comment down below about anything else that’s bugging you.

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